This harness is formerly known as our 18 circuit kit. Click here to read about the recent changes.

This 28 circuit kit will provide you with all those power accessory circuits you have been looking to add to your pickup chassis. You'll find that the ample wire lengths make this kit especially suited for trucks with long beds and extended cabs. This kit comes with the GM column mounted ignition switch connector. Included with this harness are the following parts; a GM engineered fuse block & Painless mounting bracket; GM turn signal connectors; pre wire plugs for the headlights & dimmer switch; and each wire is custom printed with the circuit identification as well as using GM color codes for easy installation.

ECM Flash Program

This is a basic start and run tune that we only recommend for a near stock application. We will only change the following parameters: delete VATS/PASS-KEY security, cooling fan on/off temperatures, rear end gear ratio, tire size, speed limiter, rpm limiter, idle rpm, and we will adjust the check engine light parameters. If your setup requires any other parameters tuned you will need to locate a local tuner. All ECMs are left unlocked to allow easy access for your tuner.

Step 1: Purchase one of the qualifying part numbers. See below for that list.

Step 2: If your part number is highlighted RED proceed to step 3B. If your part number is highlighted BLACK, proceed to step 3A.

Step 3A: If you have arrived at this step, your harness does not come with an ECM and you must provide one to be flashed. Please reference the manual with your harness to confirm the ECM part number required.

Step 4A: Once you have received your harness, please cut the Barcode label from the box as shown in the picture below.

Step 5A: Package and mail your ECM along with the Barcode label, a copy of your purchase receipt, and your ECM form that you are about to complete. (The address will be provided after you complete the form). We will pay for return ground shipping*. If you request a faster service, you will need to provide a return label.

Step 3B: If you have arrived at this step, your purchase comes with an ECM. You must fill out our ECM form BEFORE your purchase will ship. Proceed to Step 6.

Step 7: Once we have the ECM, we will use the data from the form to flash the ECM. Then, once it has been flashed we will package the ECM and ship it back to you. If we encounter a question, we will contact you. This process can take 1-3 days.

Step 8: Once you receive your ECM, it is ready to go.

*Note: Our free return shipping is ONLY good for the lower 48 states, via ground UPS. If you are outside of those states, you must provide a return shipping label with your order. If your purchase comes with an ECM, the shipping will be covered via the retailer you purchased from.